Process of treating textiles with half-acid amide derivatives



Patented Oct. 24, 1950 PROCESS OF TREATING TEXTILES WITH HALF-ACID AMIDE DERIVATIVES Chester M. Himei, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation Delaware No Drawing. Application October 23. 1945,

- Serial No. 624,103

12.0mm. (01. iii-ms) This invention relates to a method of treating textile fibers. In one of its more specific aspects, this invention relates to a method of impregnating textile fibers with cyclic imides.

The process of the present invention provides a method of treating textile fibers and fabrics to impart desirable properties thereto. It is well known that textile fibers generally possess some undesirable properties, such as lack of water resistance, vulnerability to attack by insects, and lack of uniformity in the application of dye materials. The present invention provides a method of treating textile fibers whereby undesirable properties inherent in many textiles can be modified or changed. In many applications the cost of treating textile fibers is of paramount importance. An important feature of this invention is that it provides a process of treating textiles which is simple and effective, and one which can pregnated in a fiber and converted to a water inbe carried out with a minimum of processing cost.

Textile treating agents can be roughly divided intotwo classes, those that are impregnated directly, and those that are developed within the interstices of the fiber. In general, the latter method usually leaves the fiber in a more acceptable condition due probably to the fact that the reaction is carried out within the fiber. In many cases, it is difllcult to carry out the developed type of impregnation since the reactions are sometimes difiicult to control at reasonable temperatures and low cost operating conditions. The present invention provides a process whereby a textile treating agent is rendered water soluble for ease in impregnation and is then made permanently water insoluble by a simple washing and heating process. Aqueous solutions are used in the process of the present invention, thereby providing a low cost vehicle for the reaction and eliminating the danger and fire hazard of the usual organic solvents.

An object of this invention is to provide a method for the treatment of textile fibers. Another object is to provide such a method wherein the textile fibers may be impregnated with a cyclic imide. Another object is to provide a method of treating fibers wherein certain desirable properties may be imparted thereto. Another object of this invention is to provide a process for treating textile fibers to impart desirable properties thereto wherein water is used as the vehicle for the treating agent. Still another object is to p owithin the fiber a water- ,uble cyclic imide which is not removed by normallaundering and other water washing. Cyclic imides may be used in accordance with my invention as dye leveling agents, water repelling agents, mothproofing agents, or fiame resisting agents for imparting various desirable properties to the fabrics. Other uses will occur to those skilled in the art.

I have found that improved physical properties may be imparted to textile fibers and fabrics by treatment in accordance with the method herein disclosed. These improved properties are the direct result of a process wherein a normally water soluble compound is developed within the fiber and changed to a normally water insoluble comp imd which has the property of imparting to the treated fiber the characteristic desired. The process is concerned with a method whereby a water soluble intermediate compound can be imsoluble cyclic imide by the simple process of washing and heating to temperatures below the decomposition point of the fabric being treated. The cyclic imides which are useful in the present as invention are those having five or six members vide by the method of this invention an improved textile fiber.

The process of the present invention provides a method of treating textile-fibers by developing in the imide ring. The compounds which are particularly useful are the cyclic imides produced by the dehydration of a half-acid amide of a dibasic acid selected from the group consisting of maleic, succinic, glutaric, and phthalic acids.

their analogues and homologues including the chlorine substituted derivatives of these compounds. In general, the half-acid amide of a dibasic acid capable of forming a cyclic anhydride having from five to six carbon atoms in the ring is useful in the present invention. The half-acid amides useful in the process are, of course, prepared from the selected dibasic acid or its an-.

hydride and a primary amine. The half-acid amides of secondary amines are inoperative in my process.

The half-acid amides of the dibasic acids preferred for use in the present invention are for the most part, water insoluble or difllculty soluble. The water solubility can be increased to a suitable level by the use of alkali, such as sodium or potassium hydroxide or other bases which form soluble salts of the half-acid amide. In accordance with this invention, an alkaline aqueous solution of the half-acid amide of the desired dibasic acid and primary amine is prepared and the fiber is impregnated with this solution. The salt of the aeaaoes 3 e. g. hydrochloric acid, which convertfizaid salt to the less soluble half-acid amide. In his step of the process the half-acid amide, which is water insoluble or only slightly water soluble, developed within the interstices of the fiber. The treated fiber at this stage is not alkali proofor launder proof since a simple alkaline wash would remove much of the impregnant. I have found that the fiber containing the half-acid amide canbe made permanently resistant to the effects of laundering by simply heating the fiber containing the half-acid amide to remove water, dehydrating veloped cyclic imide is, of course, highly water in soluble and water resistant.

The reactions involved in carrying out the process of the invention may be illustrated by a specific example in which a half-acid.amide of phthalic acid is employed. A half-acid amide of phthalic acid is represented by the structural formula:

where R represents an alkyl, aralkyl or cyclealkyl group. In an alkaline aqueous solution,

for example sodium hydroxide, the alkali salt of the half-acid amide is formed:

Upon contacting theimpregnated fiber with an aqueous solution of a strong mineral acid, the half-acid amide is again formed as represented by formula I above. Upon dehydration the halfacid amide is converted to the corresponding cyclic imide:

Various imides which may be employed in the process of this invention are useful as dye leveling agents. When the textile fiber-or fabric to be dyed is first treated in accordance with the present invention, subsequent dyeing results in evenness of color throughout. Impregnation of fibers with cyclic imides by use of my invention may be employed to render the fibers flame resistant. The imides which give best results as fiameproofing agents are those which contain halogens, particularly those which contain 40 to 60 per cent halogen on a weight basis. These also have good mothproofing qualities. The cyclic imides best suited for waterproofing fabrics are those containing at least sixteen carbon atoms per molecule and preferably more.

The half-acid amide for use in the process of my invention maybe made by reacting a primary amine with the desired dibasic acid, or with a suitable derivative thereof such as. for example, the anhydride of the dibasic acid. Halo-substituted acids, acid anhydrides, and the like may be employed, such as, for example, tetrachlorophthalic acid. Primary aliphatic aromatic, and alicyclic amines and halo-substituted derivatives thereof are suitable for use in the preparation of the half-acid. amide. The reaction between the anhydride and the primary amine is best carried out in the presence of an inert diluent to control the temperature and viscosity of the reaction mixture. chloroform and toluene, for example, have been found suitable for use as diluents but other solvents can be used in this preparation. Alternately, the half-acid amide can be prepared by partial hydrolysis of the diamide.

The half-acid amide is converted to the cyclic imide by heating. In general, the process of imide formation takes place at a temperature above about 200 F., the higher molecular weight amides requiring a temperature within the range of 250 F. to 350 F. I have found that the half-acid amides impregnating textile fibers may be converted to the corresponding imides at temperatures below those which cause damage to the fibers which are not melted or decomposed at the temperatures used in the process.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following examples which are given merely to further illustrate the invention and are not to be construed in a limiting sense, all parts given being by weight.

EXAMPLE 1 Preparation of N-cuclohezylphthalamic acid EXAMPLE 2 Preparation of N-dodeculphthalamic acid Dodecyl amine mole-92.5 g.) was dissolved in 400 ml. toluene and stirred during the addition of phthalic anhydride (0.5 mole-74 g.) The reaction temperature was held at -1'l5 F. during the addition of the phthalic anhydride. The toluene solution was washed several times with large quantities of hot dilute hydrochloric acid to remove excess amine and phthalic acid. Emulsions were broken or controlled by suitable additions of acetone or methanol. The purified phthalic acid was extracted as the sodium salt and was precipitated from aqueous solution by acidification. The product on drying had M. P. 192 F. and a neutral equivalent of 334 (calc. 333). Heating at 250 F. caused water to be evolved giving the imide, M. P. 147-149 F.

EXAMPLE3 Preparation of N-hexadecyltetrachlorophthalamic acid The phthalamic acid from hexadecyl amine and tetrachlorophthalic acid was prepared by the procedure outlined in Example 2. The free phthalamic acid was dissolved in aqueous caustic and used as a textile impregnant.

EXAMPLE 4 Waterp oofing of cotton textiles A 5% solution of Nu-hexadecyltetrachlorophthalamic acid was prepared in aqueous caustic solution. Cotton squares were impregnated with the solution, squeezed dry and then added to a dilute acid wash containing 10% hydrochloric acid. The cotton was then thoroughly washed with water to remove mineral acid and subsequently dried and heated to 300-350' 1". for one to five minutes to cause permanent water repellaney in the fabric.

EXAMPLE 5 Chlorinated phthdlmnic acid EXAMPIE 6 Due leveling agent The phthalamic acid from phthalic anhydride and (trihydroxymethyl) methyl amine,

(CH:OH):CNH2, was prepared and used as a cotton impregnant. Imide formation was carried out very carefully at 250-300 F. The product had improved dyeing characteristics over that shown by untreated cloth.

Since certain changes in carrying out the above process, and certain modifications in the product which embody the invention may be made without departin from its scope, it is intended that all matter contained in the foregoing description shall be interpreted as illustrative and not in the limiting sense.

I claim:

1. A process for treating textile fibers which comprises impregnating the fibers with an alkaline aqueous solution of a half-acid amide of a dibasic acid selected from the group consisting of maleic, succinic, glutaric, and phthalic acids. contacting said impregnated fibers with an aqueous solution of a strong mineral acid, and subsequently converting said amide to the corresponding imide by heating said fibers at a temperature within the limits of 200 to 350 F.

2. A process for treating textile fibers which comprises impregnating the fibers with an alkaline aqueous solution of N-hexadecyltetrachlorophthalamic acid, contacting said impregnated fibers with a dilute aqueous solution of a strong 6 mineral acid, and subsequently heating said fibearsso to a temperature within the range of 300 to ,F.

3. A process for treating,textile fibers which comprises impregnating the fibers with an alka- 5. A process for treating textile fibers which" comprises impregnating such a fiber with an alkaline aqueous solution of a half-acid amide derivative of a primary amine and a di-basic acid capable of formin a cyclic anhydride having from 5 to 6 atoms in the anhydride ring, said half-acid amine containing from 12 to 24 carbon atoms in the molecule, contacting the impregnated fiber with an aqueous solution of a strong mineral acid, and then heating the impregnated fiber at a temperature within the limits of 200 to 350 1''.

6. A process for treating textile fibers which comprises impregnating such a fiber with an alkaline aqueous solution of a halogenated halfacid amide derivative of a primary amine and a di-basic acid capable of forming a cyclic anhydride having from 5 to 6 atoms in the anhydride ring, said half-acid amide containing from 12 to 24 carbon atoms in the molecule, contacting the impregnated fiber with an aqueous solution of a strong mineral acid, and then heating the impregnated fiber at a temperature within the limits of 200 to .350 F.

7. A process in accordance with claim 6 where-' in said half-acid amide is chlorinated.

8. A textile fiber impregnated with a cyclic imide containing from 12 to 24 carbon atoms in the molecule and having 5 to 6 members in the imide ring.

9. A process for treating textile fibers which comprises impregnating such, a fiber with an alkali metal salt of a half-acid amide derivative of a primary amine and a di-basic acid capable of forming a cyclic anhydride havin from 5 to 6 atoms in the anhydride ring, said half-acid amide containing from 12 to 24 carbon atoms in the molecule, contacting the impregnated fiber with an aqueous solution of a strong mineral acid, whereby said alkali metal salt is hydrolyzed in situ, and then heating the impregnated fiber at a temperature within the limits of 200 to i350 F., whereby the half-acid amide is dehydrated in situ to form the corresponding imide.

10. A process for treating textile fibers which comprises impregnating such a fiber with an aqueous solution of an alkali metal salt of a halfacid imide derivative of a primary amine and a di-basic acid capable of forming a cyclic anhydride containing from 5 to 6 atoms in the anhydride ring, said'half-acid amide containing from 12 to 24 carbon atoms in the molecule, contacting the impregnated fiber with an aqueous solution of a strong mineral acid, whereby said alkali metal salt is hydrolyzed in situ, and then heating the impregnated fiber at a temperature within the limits of 200 to 350 F. for a time within the range of from 1 to 5 minutes, whereby the halfor! acid 18 hydrochloric acid.

1 acid amide is dehydrated in eitu to form a correepondinz imide,

11. The process 01 claim 1 wherein said min- BEFEBENOESQITID 'ihei'ollowmgreterenceeareoi'recordinthe me of this patent:

12. The woeelsor claim 1 wherein said mu- UNITED BTA'IIB PA'rln'rs acid amide is a derivative of phthaiic acid and- Number Name. Date (trihydroxymethyl) methyl I-mlne- 2,072,770 Reid Mar. 2, 1937 1a. The process or claim '1 wherein said a 2,310,873 sauer Feb. 9, 1943 acid amine is chlorinated N-dodecrl phthaiamic 2,398,272 Aelony P 6 10 Certificate of Correction Patent No. 2,526,948 October 24, 1950 CHESTER M. HIMEL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 10, for vulnerabiilty read vulnerability; column 3, line 6, for stage read state; column 4, line 75,. for phthali'c read phthalamic;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of January, A. D. 1951.

THOMAS F. MURPHY,

I Assistant Oommz'aeioher of Patents. 

1. A PROCESS FOR TREATING TEXTILE FIBERS WHICH COMPRFISES IMPREGNATING THE FIBERS WITH AN ALKALINE AQUEOUS SOLUTION OF A HALF-ACID AMIDE OF A DIBASIC ACID SELECTED FROM THE GROUP CONSISTING OF MALEIC, SUCCINIC, GLUTIC, AND PHTHALIC ACIDS, CONTACTING SAID IMPREGNATED FIBERS WITH AN AQUEOUS SOLUTION OF A STRONG MINERAL ACID, AND SUBSEQUENTLY CONVERTING SAID AMIDE TO THE CORRESPONDING IMIDE BY HEATING SAID FIBERS AT A TEMPERATURE WITHIN THE LIMITS OF 200 TO 350*F. 